Turbo Guys Comment on this Dyno Sheet

[carmad]

Only got one decent run of the three, in 4th gear, 92 octane gas.
HP and torque little lower than I expected, 365 and 400, was hoping for at least 400 and 450, used big fans but intercooler was a little hot to the touch from heat soak. Don't know how much difference that would make.
Running a little rich at the low end, needs some tweaking.
Any comments.

[beepbeep]

Well, there is not much to be said. Looks fairly good. Typical fully tweaked "I run out of breath at the top" CIS-dyno. It is too rich almost the whole range and I believe there is power to be made by leaning it out somewhat.


Install EFI, lean it out to 12.8 troughout the range and you'll gain 30+hp on the top from airflow alone + more torque in the middle.

[carmad]

Thanks Goran, I built it more for low/middle power and reliability. EFI is the way to go, but for the little extra gain I will get, I,d rather spend the money on safety equipment at the moment.

[Craig 930 RS]

Surprised you are that rich. Hard to do.....congratulations. ESPECIALLY at 1 bar -
I would have liked to see what it looks like above 6,000....perhaps up to 6,500. Anything above that isn't necessary.

Hallacious torque, J. I'd be happy with your setup.

If you are interested, here is a friends' 930 chart - on a different make of dyno, however:



And my 930 - in pen on Lyall's chart:

[Craig 930 RS]

Mine was 418 at the wheels, 376 lb ft ATW.

[RarlyL8]

Why did you stop at 6000rpm? Curious to see what it runs up to redline.
I aggree that EFI ain't worth 30hp for the thousands of dollars it cost. Just hit the boost another 0.1bar.

[Craig 930 RS]

EFI is worth it if:

AFRs are leaning out
Car sees track use in warm or hot weather
Car is modified to efficiently use EFI

Otherwise, be happy with CIS. My car.....she's on the edge.

[carmad]

Craig, thanks for posting those comparisons, makes. me feel I,m in the ballpark for all the money spent. The car pulls like a train. I will be at Willow Springs next Wednesday to give it a thrashing, last time at Buttonwillow was running stock boost and intercooler, on the street the difference huge.. Will need multiple underwear changes for the big track at Willow.

Rarly,
Set to 6000 rpm because I thought the guy might over rev the engine. Ended up I did the dyno runs, but left it at 6000 anyway.
I have had it at 7000 on the track accidently, no untoward effects. Could run a little more boost, but longevity and reliability are more of a concern.

[Craig 930 RS]

Next spring and summer, be careful at 1 bar. Hot days and not enough octane = death.

[slow&rusty]

Those are excellent numbers.....your set-up is near identical to mine, and that is what I would expect. I would be happy with that to be honest.

Yasin

[slow&rusty]

Wait a sec....are you running factory \ stock exhaust manifolds? I notice in your header you have a dual 3" GHL muffler.

You can pick up another 30hp approx by switching over the B&B or GHL headers or if you have the $$$ Marco M. headers.

Just a thought.

Yasin

[carmad]

Craig,
I only run on track with 110 octane, ran at Buttonwillow in the summer 95 degrees, oil temp was fine, car ran like a champ.

Yasin,
Still running the stock manifolds, learning to weld, so when I get better at it will try to fab my own.

[Craig 930 RS]

I like home fab efforts, but exhaust temps are sooo high in a Turbo that there would be no way in hell I'd try to fab my own.....you've got too much to lose.

[carmad]

Craig, you might be right. I will fab a J pipe for the turbo and a straight pipe for the wastegate. See how they stand up to the temps.
Do you run a J pipe straight off the turbo? If so how loud is it.

[David]

Looks like a really smooth curve. I'd worry a little about going over 12 AFR on full boost at the track, but if you're running 110 fuel I think you're safe.

[Craig 930 RS]

Any item that involves routing *before* the turbo......be careful.
Bits break off and are ingested into the turbo........BIG problems.

Post turbo, more leniency. My 930 has a 'cherry bomb' straight through style "muffler", ceramic coated. Very deep, quite loud but not a problem:



This is a catalyst, but the muffler on now is very similar except the silencing portion is 2X as long as the catalyst. And finished with the mentioned coating.

[BlkBird]

Not that I pretend to understand but are your results absolute values or corrected for temperature, humity, etc. I guess that means SAE values?

Just for comparison here is Blkbird's dyno results on 93 octane. I'm told there is an extra 30HP waiting but I have to promise to run 100 octane or better before I'm allowed to ask for it. You can see the original K27 7200 numbers and then the results after the turbo has been "tweaked". And these are not SAE figures - apparently those would be considerably greater (see notes by tester: 422 HP and 466 ft-lbs)?

I have also been told I'm near the limits that the cabriolet frame can handle. Which is fine by me. But I am impressed that a motor with 80K miles can still pull so hard and scare me so much.

[yasir]

What gear are we suppose to dyno our 911's in asking 'coz i only managed 275 at the wheels in 3rd gear on a Mustang dyno :
Btw this is in a 1991 C2 Turbo with 1 bar spring and B&B headers/exhaust.Would i have made more power in the 4th gear ?
Thanks

[carmad]

I don't know the answer, but he first run I made was in 3rd gear and it made 225hp, I did the other two runs in 4th. First time on a dyno, so was maybe babying it a bit.

[RarlyL8]

I am amazed that you're getting 365hp using stock heat exchangers. You'll get your 400hp goal with a Euro or aftermarket exhaust.
I run mine up to 7,000rpm when "racing". (ARP studs and bolts) Pulls hard all the way through. I only notice a slight drop off in power above 6,000rpm in 4th and 5th gears. Configuration is identical to yours with a Euro exhaust.

I wouldn't run more than 1.0bar of boost with CIS. You'll get the power you desire from the exhaust mods.